Sirtuins are regulators of the proteome by modifying metabolic enzymes, chaperones and anti-oxidative stress proteins to improve the response of organisms to several environmental stressors. We tested their role in two marine mussel species that vary in their response to heat and salinity stress. A key question for integrative biology is if these molecular differences affect phenotypes at higher levels of organismal organization. We tested this assumption while simultaneously monitoring the molecular changes accompanying changes in ciliary activity, particle velocity of the gill, a feeding organ in mussels, and whole organism filtration rates. The presentation will discuss the challenges of doing integrative biology.